What sort of information is there floating around about the pre-OYW UC timeline? I'm specifically wondering about the circumstances that lead Side 3 to break away from the Earth Federation. Was the Earth Federation actively oppressing the spacenoid population to the point where they were willing to fight for independence, or was it more of a more of a palace coup done without much in the way of widespread support? What was the Earth Federation's reaction to Side 3 going rogue? It's mentioned in most timelines that they organized the EFSF in response to Zeon arming itself and that they imposed "economic sanctions", but are there any details to that?

A few other pre-OYW tidbits of information have peaked my interest as well. Mark's timeline mentions that in 0067, the Earth Federation "rejects a motion for colonial autonomy." What's that all about? Which colonies made the request, and what exactly do they mean by "autonomy"? Does that mean actual complete independence, or just more local control and less centralized authority?

I'm curious about the independence of Side 6, as well. When Side 3 broke off, the Earth Federation apparently didn't have any military presence in space to speak of, so it makes some sort of sense that by the time they built one up, Zeon would have one as well, so it wouldn't be worth the cost of fighting them. Side 6, however, didn't declare independence until 0077 -- had they wanted to, the Earth Federation certainly could have kept them in line by force. It is mentioned that Zeon sent Zaku Is to support Side 6, but I find it hard to imagine that any serious fighting went on (otherwise, the Federation wouldn't have been caught so off guard during the One Week Battle). It seems strange to me that the Federation would simultaneously piss the colonies off enough to make them want to rebel, but wouldn't use their military to keep them from seceding. There's also the fact that, post-OYW, Side 6 seems to become part of the Federation again, and no mention of its former independence is ever made again. At least Side 3 maintained an independent existence as the Republic of Zeon after the One Year War (even if it was something of a vassal state). Side 6 doesn't even get mentioned as being brought back into the fold -- it's just EF territory again, and its former independence is never brought up.

The fed in the timeline in 0060 launchs Armament Reinforcement Plan. Since it is "reinforcement" probably the fed has some forces in space, but not a full branch [hence setting up EFSF as a full force in 0059 - augmenting the economic sanction]?

The fed in the timeline in 0060 launchs Armament Reinforcement Plan. Since it is "reinforcement" probably the fed has some forces in space, but not a full branch [hence setting up EFSF as a full force in 0059 - augmenting the economic sanction]?

Mark's timeline indicates that along with the Armament Reinforcement Plan, Luna II is converted into a military base in U.C. 0060. I suppose that the Type 61 MBT might be a result of this plan since the Federation commonly uses the development year in the model number of their weapons.

As you mentioned, the EFSF is established just the previous year, U.C.0059, so most likely they didn't have any space use military vessels and other weapons. Since the Salamis and Magellan aren't produced until U.C. 0070 during the next Armament Reinforcement Plan, it's possible that the result of this plan includes the Columbus class and some early space fighter.

Just for comparison, in Gundam 00 the first space military vessels are supply ships, although these have been outfitted with some weapons. Another example found in U.C. is the Papua, which originally was a missile cruiser when it was first rolled out in U.C. 0069, but in U.C.0074 s new improved version of the Papua is comissioned, now reclassified as a supply ship. I suppose it could be possible that the early Columbus were outfitted with some weapons before the Salamis and Magellan were introduced.

No one else has anything? I know pre-OYW info is pretty sparse, but I was hoping that 30+ years of Gundam history had shed at least a little light on the subject.

Really, what I'm most curious about is Zeon's justification for rebelling. The Federation seems to more or less ignore the Sides between the period when they're built and populated and the One Year War. It seems odd that they would bother to rebel when they weren't really being mistreated -- was Zeon's rebellion entirely ideological? It seems unlikely to me that he'd be able to convince a whole Side to declare independence without the Earth Federation being actively oppressive, but whenever anyone talks about Spacenoid independence, they talk about "souls weighed down by gravity" rather than "Earth Federation taxes are too high" or "spacenoids are being disenfranchised by Earth Federation policies".

It's an interesting question, but there seems to be a dearth of info on the topic.

From what I've seen there really wasn't that much Earth Federation abuse if at all? (Though we know that many of the leaders were corrupt and incompetent...)It seemed more like the Feds just wanted to control the colonies from Earth and the colonists didn't like that idea...

Zeon Deikun started a revolution. And the Zabi's saw an opportunity, and killed him, and established the Duchy of Zeon. Then declared war against the Federation hoping to conquer the entire Earth Sphere, using the Federation as a scapegoat.

You don't see any other colonies completely joining side 3. In fact Zeon actually slaughtered some of the other colonies.

So from what I've seen it's just a case of a bunch of dictators in space fighting the other ruling body.

From what I've seen there really wasn't that much Earth Federation abuse if at all? (Though we know that many of the leaders were corrupt and incompetent...)It seemed more like the Feds just wanted to control the colonies from Earth and the colonists didn't like that idea...

Zeon Deikun started a revolution. And the Zabi's saw an opportunity, and killed him, and established the Duchy of Zeon. Then declared war against the Federation hoping to conquer the entire Earth Sphere, using the Federation as a scapegoat.

You don't see any other colonies completely joining side 3. In fact Zeon actually slaughtered some of the other colonies.

So from what I've seen it's just a case of a bunch of dictators in space fighting the other ruling body.

Actually there could are other factors that led the colonists to rebel and accept Zeon Zum Deikun. I will point out a few:

First, the classic problem of "ruling Space from Earth". This is best exemplified by what is said by Blex Forer during the Gryps War, in which the Earth Federation Politicians terminally refuse to head to space, giving several different excuses, and this ultimately keeps them from having a realistic perspective on the situation of space, including the spacenoids problems and needs, or as in Zeta, the oppression of the Titans. We don't quite know how good or bad the situation was before the independence of the Republic of Zeon, but I have an idea of what might have led that the first rebellions took place at Side 3 rather than anywhere else, which probably led to Zeon Zum Deikun to begin his peaceful independence movement there, which takes us to a second issue:

OVERPOPULATED COLONIES

As you might already know, Side 3 is the only Side that uses the closed type colonies. We are never quite told why this is the case, though we can assume that it might be related to their position behind the moon, their distance to Earth, or them being an experiment of sorts to review the efficiency of this type of colony. I advise that you check the following pages for interesting information on both types of colonies:

Basically, Closed Type Colonies are more economically efficient and can hold about twice the population, but the psychological effects of the closed environment make them only a third as pleasant. This problem could be one of the causes that led to the discontinuation of the Closed Type Colonies.

I should mention the exceptions, first the Gryps Colony (and almost a decade later the Industrial 7 Colony). Although its uncertain when it began construction and if the Titans or at least Jamitov might have influenced on the decision of it being a Closed Type Colony, this eventually served the Titans needs for a military headquarters and weapon production facilities, an aspect mentioned on the Closed Type Colony article.

Back to Side 3, the most common theory regarding its population is that it held twice as much population as any of the other Sides, which are supposed to have about 1 billion habitants, which seems confirmed by the casualties each Side suffered during the One Week War as mentioned on the footnotes of Mark's timeline. Furthermore we are told that Open Type Colonies could hold up to 10 million people. But then each Colony Article brings a different theory on the population a of Closed Type Colony:

-The Open article says that due to environmental strain they should hold only about 1.5 times the population of Open Type Colonies, basically 15 million people (although later in some later parts he simply doubles the population amount to make some quick calculations).-But the other article makes a sum of the people living on each section of a Closed Type Colony, which gives a total of 36 million people per colony.

In order to reach the figure of 2 billion people at Side 3, we would need either 133 colonies housing 15 million people each or 55 colonies housing 36 million each. However as MS Igloo Apocalypse shows from time to time, there are only 40 colonies at Side 3. While this figure seems small, its consistent with what is mentioned on the Mark's timeline footnote, which indicates that Side 5 was supposed to have 42 colonies, from which only 30 were completed. In Dyar Straights, the author proposes that each Side should have between a 100 and 150 colonies to meet the adequate population density, and uses as reference that the highest numbered colony ever mentioned in Gundam is bunch 85 from Side 2 during Zeta Gundam, indicating that this might only be the middle range. But on an article regarding the Sides, the author agrees with one of Mark's theories that by Zeta, the Sides have been reorganized and the new Side 2 at Lagrange Point 4 is actually the merge of Side 2 and Side 6.

If Bunch 85 of Side 2 is actually on the top of the range rather than on the middle, that would mean that the entire Side has about 85 colonies which are the sum of the original side 2 and Side 6. With this, Side 2 and Side 6 would each have just over 40 colonies a piece, which fits perfectly well with what has been mentioned on Igloo and on Mark's footnote.

This lead us to one conclusion: by U.C. 0079, the colonies are overpopulated. With around only 40 colonies by Side, most Sides would have an average population per colony of 25 millions, 2.5 the people than they should house if we consider the 10 million figure. For Side 3, each of its 40 colonies would have a population of 50 million in order to meet the 2 billion figure. This would also be 2.5 more population than the 20 million per colony (or over 3.3 times if we considered the 15 million figure instead), but it would only about 50% more population if we consider the 36 million figure per colony.

The overpopultion problem could even be confirmed on 0083, when we are told that the colonies that are eventually hijacked by Cima's marines were supposed to be sent to Side 3 due to the overpopultaion problem over there. This would be a case of overpopulation just 3 years after a war that should have resulted in the loss of a considerable part of the Side's population.

So basically this leaves us with Side 3 having a 50% excess population in the best scenario, a problematic situation further affected by the fact that it takes place on the less pleasant type of colony to live in.

Furthermore, there are other issues such as spacenoids not being allowed to go to Earth, best exemplified by the whole illegal immigrant situation of Uso and Shakti on Victory, the appointing by the Federation government of the colonies' authorities, as pointed out by Full Frontal on Unicorn's second episode, including all the negative consequences that result from this in a non democratic government, or the issues that will be covered in future Unicorn episodes (if they follow the novels). However this post is already too long, so I will cover that at another time.

The problem with the Colony 85 example is that with the Sides combined, there's every chance that the colonies were renamed -- especially as so many colonies were destroyed in the One Year War. If the colonies were renamed & renumbered, this would mean that the new Side 2, after its surviving colonies were merged with Side 6, still had at least 85 colonies. This would suggest that in each pre-war Side 40 colonies would be a low-ball number.

Even better for the more-than-40 colonies argument is the fact that the Gundam canon never claims more than 10 million people per colony -- even the one closed-type colony provided with a population (Mahal, before it was a colony laser) had only 6.5 million. To reach our 1-billion-per-Side figure with an upper limit of 10 million bodies per colony, we need at least a hundred colonies. Mahal's 6.5 million is twice the 3 million people at 30 Bunch when the Titans introduced poison gas, but if it was average for Side 3 pre-war, then to hit 2 billion people Side 3 would have 154 colonies.

Seemingly unnoticed by Dyarstraights, however, is the fact that, as Sweetwater demonstrates in CCA, the closed-type colonies do not have the same dimensions as the open-type, but rather are significantly smaller in diameter, somewhere between 1/2 and 2/3 the size of the open-types. This fact makes Mahal's 6.5 million considerably more crowded than the 8 million of Side 2's 21 Bunch in 0087, since that's an open-type colony.

The lack of clear evidence of what the population density per-colony was pre-OYW makes it quite difficult to determine if moving people into space improved people's living conditions or not.

The problem with the Colony 85 example is that with the Sides combined, there's every chance that the colonies were renamed -- especially as so many colonies were destroyed in the One Year War. If the colonies were renamed & renumbered, this would mean that the new Side 2, after its surviving colonies were merged with Side 6, still had at least 85 colonies. This would suggest that in each pre-war Side 40 colonies would be a low-ball number.

I don't think 85 colonies might be so difficult to achieve, especially in the newly formed Side 2 which would include the former Side 6 which was unaffected by war. Let's remember that not all colonies were destroyed by nukes, but also some were gassed, which basically left them intact. From the ones that do were nuked, it's quite possible that only a section of the colony was damaged by the nuke, especially considering that the nukes fired by Zaku bazookas seemed to have low power, as evidenced in some of the footage from Gihren's Greed showing that only individual Federation warships were destroyed by them. It's far more possible that the actual damage was done to the windows of the colonies which would be the more fragile sections, which would allow a larger area to be destroyed with less firepower and thus leading to a faster loss of pressure, but in turn are the easiest section to replace as they lack any other facilities.

Furthermore, these are located at one of the two Lagrange points with stable equilibrium. Let's consider why the Sides at L4 and L5 were not considered a single Side from the beginning. The most likely explanation would be because they were built in different stages.

Mark's timeline indicates that construction of Side 3 isn't started until Side 2 is completed. This indicates that the two or more Sides were not built at the same time. We know that Sides 1, 2 and 4 all held around the same population of 1 billion, but Side 5 was left uncompleted, yet construction of Side 6 took place. My guess is that construction was halted due to priority been given to construction of colonies at the stable Lagrange Points: L4 and L5. Afterwards, construction at Side 5 continues, but is completely terminated by U.C. 0051, along with the colonization project. Construction of Side 7 doesn't start until December of U.C. 0070, when Luna 2 is also moved to L3, but this could all have been part a strategic movement of the Federation which at the time is already preparing its space forces.

Also, it would make perfect sense that for the new Side 2 to have received additional colonies just like Side 3 to deal with overpopulation, result of Side 6 neutrality during the OYW. It makes more sense for empty colonies to be moved to Side 2, than moving millions of civilians to from L4 to L5.

Taking all these into consideration, the new Side 2 could have easily had over 80 colonies due to the population concentrated on L4, unlike the most likely small population left at the new Side 1.

Black Knight wrote:

Even better for the more-than-40 colonies argument is the fact that the Gundam canon never claims more than 10 million people per colony -- even the one closed-type colony provided with a population (Mahal, before it was a colony laser) had only 6.5 million. To reach our 1-billion-per-Side figure with an upper limit of 10 million bodies per colony, we need at least a hundred colonies. Mahal's 6.5 million is twice the 3 million people at 30 Bunch when the Titans introduced poison gas, but if it was average for Side 3 pre-war, then to hit 2 billion people Side 3 would have 154 colonies.

However Mahal is probably on the colony with lowest population on Side 3. Consider this: if Gihren was in a rush to get the Solar Ray operational, he needed to empty a whole colony and it would only make sense to empty the one with lowest the population. This is consistent with the fact that they didn't even kept any record of the people they evacuated.

As to why Mahal had a low population, I do have a theory, although I hardly have anything to back it up, but it you are interested:

The colony was probably used as ship yard for producing warships. Let's remember that by the end of the war Zeon ahs decided to cancel their plan to build the vastly improved Late Production Musai (0083 version) to produce the more economical Final Production Musai, which is meant to be produced in large numbers to close the large gap between the numerical size of both sides space fleets. Oddly enough any ships yard hardly seen despite them being around since at least two weeks before the end of the war, when two of them participate in the Kampfer's infiltration on December 15th. It would also seem strange for Zeon not to build the Final Production Musai to quickly rebuild its fleet after the war, over the Musai Kai (Z version), and even if the extra firepower is given as the justification, it would not make sense to built it over the improved Late Production Musai then. Another reason should exist.

Now, Zeta showed us that the Dogosse Gier was built inside a colony (much like the Minerva was seen in Gundam Seed Destiny). If this colony was the designated place where the Final Production Musais were being built, it could mean that by that time a lot of space within the colony was taken for expanding the ship yards for producing these Musais in the large numbers they were required. This led to a first move of population which reduced the population to the 6.5 million you mention. Then, by December 21st, 4 days before December 25th when Solar Ray was completed, the colony is claimed to be used for such purpose. Although it would mean the loss of the shipyards, the Solar Ray Project takes priority.

After the end of the war, Zeon has lost the facilities for the production of the new types of Musai, so it uses some older facilities at its other colonies, where the original Musais were built and the design is only slightly upgraded.

Black Knight wrote:

Seemingly unnoticed by Dyarstraights, however, is the fact that, as Sweetwater demonstrates in CCA, the closed-type colonies do not have the same dimensions as the open-type, but rather are significantly smaller in diameter, somewhere between 1/2 and 2/3 the size of the open-types. This fact makes Mahal's 6.5 million considerably more crowded than the 8 million of Side 2's 21 Bunch in 0087, since that's an open-type colony.

The lack of clear evidence of what the population density per-colony was pre-OYW makes it quite difficult to determine if moving people into space improved people's living conditions or not.

I have always had this idea that Sweetwater was built using the leftover half of the Gryps Colony. Check the first part of first Zeta movie and you will see a couple of clear shots which show that the Gryps colony seems to be composed of two large cylinders connected by an internal smaller one. After it’s converted into a colony laser, it seems to be shorter and now it’s a single cylinder. Besides, its overall design looks different from the ones shown on MS Igloo at Side 3, having a flat end with mirrors on it instead of the round ends of both Side 3's closed type colonies and open type colonies.

By the way, in Z episode 1, as Char approaches the colony he says something among the lines of the colony being built by Zeon remnants, which might explain why we have a closed type colony instead of an open type colony, plus it sounds just similar to Sweetwater's background being that it was created for the survivors of previous Zeon movements.

I don't think 85 colonies might be so difficult to achieve, especially in the newly formed Side 2 which would include the former Side 6 which was unaffected by war. Let's remember that not all colonies were destroyed by nukes, but also some were gassed, which basically left them intact. From the ones that do were nuked, it's quite possible that only a section of the colony was damaged by the nuke, especially considering that the nukes fired by Zaku bazookas seemed to have low power, as evidenced in some of the footage from Gihren's Greed showing that only individual Federation warships were destroyed by them. It's far more possible that the actual damage was done to the windows of the colonies which would be the more fragile sections, which would allow a larger area to be destroyed with less firepower and thus leading to a faster loss of pressure, but in turn are the easiest section to replace as they lack any other facilities.

Oh, man. A nuke that hits a colony is going to destroy the colony, regardless of how large or small the nuke is. GG showing nukes only able to destroy a single warship is just being accurate to science (unlike 0083). About 90% of the destructive power of a nuclear warhead on Earth is a result of the blast wave created by the superheating and subsequent expansion of the atmosphere around where the nuke is detonated. Atmosphere which doesn't exist in space. So it really doesn't matter if the Zaku bazooka is throwing tiny 15 kiloton "Little Boy" style nukes such as that dropped on Hiroshima, or if it's throwing 50 megaton "Tsar Bomba" nukes. In space, each is only going to be able to destroy a single warship, and that only if it hits or explodes within spitting distance of the ship. CCA did a much better job of showing how nuclear weapons would actually work in space than 0083 did.

Now, if that nuke hits a colony, all it has to do is get through the colony wall and it suddenly has access to a compressible atmosphere, which will most likely shred the colony cylinder as if you exploded a firecracker inside a sealed 12-oz aluminum can, because the nuke can actually produce its blast wave. If the colonies are set up in the ballistic pairs originally required by O'Neill, then the destruction of one colony will likely cause sufficient shrapnel to damage (but not necessarily destroy) the other colony in the pair. Even if that colony survives, however, it will shortly become uninhabitable as it fails to precess during its orbit of the sun, and eventually is pointed far enough away from the sun that it no longer receives light.

Even if, for the sake of argument, a colony is hit by a nuclear weapon and not destroyed outright. What's the damage? Are there whole chunks missing? If so, the colony is now unbalanced and a navigational hazard, because its orbit will no longer be predictable. At L4 or L5, it will stay in more or less the same neighborhood, but be out of sync with the rest of its Side and therefore in danger of colliding with another colony. Since there's a war going on, it's possible no one will take the time to stabilize the colony but instead either ignore it or complete its destruction. An unbalanced colony at L1 or L2 would at least leave the area of the Side altogether, and no longer be a danger to the other members of its Side.

Gelgoog Jager wrote:

Furthermore, these are located at one of the two Lagrange points with stable equilibrium. Let's consider why the Sides at L4 and L5 were not considered a single Side from the beginning. The most likely explanation would be because they were built in different stages.

L4 and L5 are "stable" in that objects there stay in the general area when nudged out of their designed orbits -- and by "general area" we're talking about the generic halo orbit the Sides are already on. And those orbits are already larger in size than the moon. For the undamaged colonies, this is actually a bad thing, because the orbits of any damaged colonies are no longer predictable and the risk of one of them straying into the path of undamaged colonies is significantly increased. How much it's increased we don't know, because we don't know the orbital period of the Sides on their halo orbits around the LaGrangian points.

Gelgoog Jager wrote:

Mark's timeline indicates that construction of Side 3 isn't started until Side 2 is completed. This indicates that the two or more Sides were not built at the same time. We know that Sides 1, 2 and 4 all held around the same population of 1 billion, but Side 5 was left uncompleted, yet construction of Side 6 took place. My guess is that construction was halted due to priority been given to construction of colonies at the stable Lagrange Points: L4 and L5. Afterwards, construction at Side 5 continues, but is completely terminated by U.C. 0051, along with the colonization project. Construction of Side 7 doesn't start until December of U.C. 0070, when Luna 2 is also moved to L3, but this could all have been part a strategic movement of the Federation which at the time is already preparing its space forces.

Strictly speaking, all it means is that Side 2 and Side 3 were not built at the same time. The official timeline seems to not give dates for the start or end of Side construction for anything other than the end of Side 2's construction and the beginning of Side 3's. Side 2 ending before Side 3 began could suggest that Side 2 is actually one of the smallest Sides.

I note on there that while the official timeline claims in 0078 11 billion humans, 9 billion of them in space, 7 billion of those in the colonies, Gundam Movie III states only "half of humanity" is in space at the start of the war. Which do we go with when looking at required population densities for colonies? Movie III's figures support the population numbers in Zeta much better than the official timeline's figures do.

Gelgoog Jager wrote:

Also, it would make perfect sense that for the new Side 2 to have received additional colonies just like Side 3 to deal with overpopulation, result of Side 6 neutrality during the OYW. It makes more sense for empty colonies to be moved to Side 2, than moving millions of civilians to from L4 to L5.

I'd have said that, like neutral territories near any major war, Side 6 should be dealing with a massive refugee population. Except, you know, that Zeon made a habit of killing anyone in its conquered Sides, which could easily cut down on the refugees from anywhere but Side 5, which actually lived long enough for significant numbers of its population to have tried running elsewhere. I'd argue that it makes more sense to move any salvageable colonies from Side 2's halo orbit to Side 6's halo orbit, and then simply renumber Side 6 as Side 2, because there are many more surviving colonies in Side 6 than in what's left of Side 2. How many colonies that would be is up for grabs, because we don't know enough about the first month of the war to figure out if Zeon preferred to nuke or gas colonies, and how many were destroyed due to collateral damage. Either way, the existence of a Colony 85 suggests that Sides had more than the paltry 40 colonies each often cited, because otherwise combining an undamaged side (Side 6) with a largely depopulated side (Side 2) should not total up to more than 80 colonies. Depending on how profligate Zeon was with with the nukes, or how many colonies were caught in cross-fire, Side 2 could easily have fewer than half its colonies surviving to be combined with Side 6 and renumbered.

Unfortunately, the only moved colonies we are certain about are via the Colony Reclamation Plans, the first of which moves colonies from the former Side 4 to Side 3 in 0082, and the second moves them from Side 1 to Side 3 in 0083. This could be because there's insufficient surviving colonies and/or surviving infrastructure to repair the colonies there, but it would pretty much have to be politics which sent the colonies to the independent Side 3 for repair rather than to L4, which would require less fuel (and thus be cheaper for the chronically cash-strapped Federation).

Gelgoog Jager wrote:

Black Knight wrote:

Even better for the more-than-40 colonies argument is the fact that the Gundam canon never claims more than 10 million people per colony -- even the one closed-type colony provided with a population (Mahal, before it was a colony laser) had only 6.5 million. To reach our 1-billion-per-Side figure with an upper limit of 10 million bodies per colony, we need at least a hundred colonies. Mahal's 6.5 million is twice the 3 million people at 30 Bunch when the Titans introduced poison gas, but if it was average for Side 3 pre-war, then to hit 2 billion people Side 3 would have 154 colonies.

However Mahal is probably on the colony with lowest population on Side 3. Consider this: if Gihren was in a rush to get the Solar Ray operational, he needed to empty a whole colony and it would only make sense to empty the one with lowest the population. This is consistent with the fact that they didn't even kept any record of the people they evacuated.

As to why Mahal had a low population, I do have a theory, although I hardly have anything to back it up, but it you are interested:

Possibly it was. However, in a tightly-controlled dictatorship, it's also entirely possible that residents of colonies are forced to move from one to another to balance the populations. Even if Mahal has the "lowest" population that tells us nothing about the average population size, just that Mahal had 6.5 million. If the average size was 6.8 million, Mahal would still have the smallest population and thus be the easiest to evacuate.

Gelgoog Jager wrote:

The colony was probably used as ship yard for producing warships. Let's remember that by the end of the war Zeon ahs decided to cancel their plan to build the vastly improved Late Production Musai (0083 version) to produce the more economical Final Production Musai, which is meant to be produced in large numbers to close the large gap between the numerical size of both sides space fleets. Oddly enough any ships yard hardly seen despite them being around since at least two weeks before the end of the war, when two of them participate in the Kampfer's infiltration on December 15th. It would also seem strange for Zeon not to build the Final Production Musai to quickly rebuild its fleet after the war, over the Musai Kai (Z version), and even if the extra firepower is given as the justification, it would not make sense to built it over the improved Late Production Musai then. Another reason should exist.

Now, Zeta showed us that the Dogosse Gier was built inside a colony (much like the Minerva was seen in Gundam Seed Destiny). If this colony was the designated place where the Final Production Musais were being built, it could mean that by that time a lot of space within the colony was taken for expanding the ship yards for producing these Musais in the large numbers they were required. This led to a first move of population which reduced the population to the 6.5 million you mention. Then, by December 21st, 4 days before December 25th when Solar Ray was completed, the colony is claimed to be used for such purpose. Although it would mean the loss of the shipyards, the Solar Ray Project takes priority.

The "other reason" that is generally cited is that the Republic wasn't permitted to rebuild its forces, which is why they're generally said to be using Rick Doms throughout the 0080s, even though they had access to the Gelgoog design. The Titan warships were built in a colony for secrecy; does Zeon require secrecy? They developed the MS-05 line in public. And, logistically, it's a hell of a lot easier to build a warship either in a space dock outside the colony (such as the one White Base tried to use in Side 6) or in the existing zero-G space dock of a colony than along the "floor" of the colony as we're shown with Dogosse Gier. Turning one of your primary industrial factories into a giant weapon strikes me as cutting off your nose to spite your face; if Zeon won, they'd need more warships to hold their territory, particularly since it was clear the Solar Ray was only going to be able to fire once.

On the other hand, a heavily industrialized economy should require a larger population than a normal colony, not a smaller one. Heavy industry tends to be manpower-intensive, particularly since we see no evidence of robot/AI-assistance in any sort of manufacture or other labor, and suggesting many tasks which today are performed by machines were still being performed manually in Gundam.

Gelgoog Jager wrote:

After the end of the war, Zeon has lost the facilities for the production of the new types of Musai, so it uses some older facilities at its other colonies, where the original Musais were built and the design is only slightly upgraded.

Or, due to treaty obligations, it forgoes upgrade options for a number of years, and when it does upgrade the Musai fleet it opts for a cheaper, less heavily armed, warship than the 0083 type Musai due to a poor financial situation.

Gelgoog Jager wrote:

I have always had this idea that Sweetwater was built using the leftover half of the Gryps Colony. Check the first part of first Zeta movie and you will see a couple of clear shots which show that the Gryps colony seems to be composed of two large cylinders connected by an internal smaller one. After it’s converted into a colony laser, it seems to be shorter and now it’s a single cylinder. Besides, its overall design looks different from the ones shown on MS Igloo at Side 3, having a flat end with mirrors on it instead of the round ends of both Side 3's closed type colonies and open type colonies.

This would go against Char's speech in CCA, however, where he states that Sweetwater is built from damage Open & Closed colonies. The non-colony-laser part of Gryps was never attacked, and therefore would be very hard to consider "damaged". Plus, as an independent object, there's no motivation to attach it to another colony fragment; it can house people exactly as-is.

Gelgoog Jager wrote:

By the way, in Z episode 1, as Char approaches the colony he says something among the lines of the colony being built by Zeon remnants, which might explain why we have a closed type colony instead of an open type colony, plus it sounds just similar to Sweetwater's background being that it was created for the survivors of previous Zeon movements.

The line is actually "I think this colony was originally built from Zeon scraps." Nice and vague. 1) Char's not sure, which opens up a nice can of worms. 2) It's unclear if this means it was built from destroyed colonies, or from leftover material from the original Side 3 construction (either could be referred to as "scraps"). And the ability of Gryps to split into two sections doesn't really help clarify.

Oh, and Mark's Timeline (0085.09.08) tells us exactly when construction began on Gryps; while this doesn't completely remove the possibility of it being relocated from Side 3, it seems unlikely.

Like so much in the messed up Gundam continuity, there's considerable latitude for the individual fan to piece things together as they see fit. Without a definite continuity, this is pretty much what we're forced to do.